ssh-wakeup.sh

#!/bin/bash

# Simple script to check if remote host behind a jump host is up. If not - wake it up using etherwake.
# Usage: invoke the script through ProxyCommand directive from your ssh_config.
# "nc" must be available on your host. "etherwake" must be available on jump host.
# Example: 
# Host <target_hostname> 
#       ProxyCommand ~/.ssh/ssh-wakeup.sh <jumphost_address> <wol_interface> <wol_mac_address> %h %p

function wait_for_host() {
        local host=${1}
        local port=${2}
        local count=${3}
        local tries=0
        TIMEOUT_SEC=1

        while (( ${tries} < ${count} )); do
                if nc -z -w ${TIMEOUT_SEC} ${host} ${port} &>/dev/null; then
                        return 0
                fi
                tries=$((tries+1))
        done

        return 1
}

function wakeup_host() {
        local router=${1}
        local iface=${2}
        local mac=${3}

        ssh -o BatchMode=yes ${router} etherwake -i ${iface} ${mac} &>/dev/null
}

function main() {
        local router=${1}
        local iface=${2}
        local mac=${3}
        local host=${4}
        local port=${5}
        readonly COUNT_CHECK=3
        readonly COUNT_WAIT=300

        if ! wait_for_host ${host} ${port} ${COUNT_CHECK}; then
                if ! wakeup_host ${router} ${iface} ${mac}; then
                        return ${?}
                fi
                if ! wait_for_host ${host} ${port} ${COUNT_WAIT}; then
                        return 110
                fi
        fi

        exec nc -F ${host} ${port}
}

main "${@}"